It is worth the hassel if you can get hold of a J so you dont have to pay rental and you get a fill on the J that charges you by the Bar rather than by the J.
As for the blenders course?
??
The O2 Hackers hand book is all you need for air top stuff.
You need to be doing a fair bit of diving to make the front end cost of a whip and decent in line presure gauge work out. Yo definatly dont want a shead load of buddies involved as you will be for ever getting the J filled.
ATB
Mark Chase